1. Joe Hart

Joe Hart was a rock at the back for Manchester City last season, winning the Golden Gloves award for the second year in a row after keeping 17 clean sheets in 38 games as the club secured their first-ever Premier League title.

The England man averaged the most minutes between conceding goals amongst regular Premier League goalkeepers in 2011-12, taking 118 minutes per goal to let in just 29 all campaign.

So what has happened this season? At Southampton, Hart palmed Jay Rodriguez's shot back into danger for Jason Puncheon to pounce before letting Rickie Lambert's weak effort slip through his hands and legs to allow Steven Davis to extend the lead.

And this wobble of form has been going on for a while, with Zlatan Ibrahimovic's inspiration of Sweden to a 4-2 win over England last November a turning point.

More interestingly, just 12 of Hart's 25 attempted passes against Southampton found their target, with just five of 18 sent over the halfway line successful as City opted for a long-ball game on more occasions than building from the back.

If you compare this to the final game of last season, when City clinched the title, Hart boasted a 92 per cent success rate – nearly double of that garnered against Saints - as just one pass missed their desired target be the range long or short.

Hart is relinquishing the ball far more than he was last season, thus putting his side under increased pressure.

Following a disastrous collective display in the 3-1 loss to Southampton, Goal.com takes a look at which players are guilty of not performing to the levels of last season as Manchester City's title challenge continues to falter.